1. Field of the Invention
The present invention relates to a hydrofoil system. More particularly, the present invention relates to a hydrofoil system for lifting a boat out of water an amount sufficient to reduce drag while still allowing the boat to be powered by a conventional inboard-outboard drive.
2. Description of the Prior Art
Numerous innovations for hydrofoils have been provided in the prior art that will be described. Even though these innovations may be suitable for the specific individual purposes to which they address, however, they differ from the present invention.
A FIRST EXAMPLE, U.S. Pat. No. 3,092,062 to Savitsky teaches in combination with a water borne vessel, a passive self-compensating hydrofoil control system comprising a substantially vertical hydrofoil strut member and a hydrofoil plane, said vertical strut member being connected at its upper end to the hull of said vessel, said hydrofoil plane being disposed at the lower end of said strut member and operable to maintain a hydrodynamic lift of the vessel to a minimum submergence of the hydrofoil plane below the free water surface at cruise speed of the vessel, each of said strut and plane members having integral pivotal flaps defining at least a portion of the trailing edges of said members, said pivotal flap of the strut member terminating at its lower end at a height above said hydrofoil plane which is greater than said minimum submergence, and mechanical linkage means interconnecting both of said pivotal flaps and operable, on application of unbalanced external forces to one flap causing it to pivot, to apply to the other flap a force acting to move said other flap toward a position for equalizing the forces applied to both flaps.
A SECOND EXAMPLE, U.S. Pat. No. 3,577,948 to Frey teaches an attachment for a power boat which fits on the transom or stern of the boat and comprises a pair of trim tabs hinged at the transom and extending rearwardly therefrom, and which may be swung vertically simultaneously to different angular positions to trim the boat so that it operates at the proper attitude regardless of its loading. The tabs are so formed that they also bring about lateral stability as well as impart the proper attitude to the boat. Furthermore, the tabs are positively moved vertically up or down to their selected angular positions.
A THIRD EXAMPLE, U.S. Pat. No. 3,651,775 to Kock teaches a hydrofoil system attached to a hull of a vessel. The foil are attached to the hull of a vessel by means of non-lifting struts and each foil comprises a main lifting foil portion which consists of submerged middle section and two upwardly and outwardly inclined side sections which control the end position of the lift. In a spaced relation and parallel to the inclined sections, two auxiliary upper lifting foil portions are attached on each side of the hull for supporting the lifting action and stabilizing the vessel.
A FOURTH EXAMPLE, U.S. Pat. No. 4,756,265 to Lane teaches a thrust collar for mounting around the upper portion of the propeller of an inboard/outboard engine. Each thrust collar supports a horizontal hydrofoil wing extending laterally from the collar. A second, similar wing can be provided on an opposing side of the collar. Where the collar is used in pairs on paired engines on a catamaran hull, a single hydrofoil wing can be supported between the thrust collars. The thrust collar is preferably used in conjunction with hull lifting structures. One hull mounted hydrofoil structure is supported at the lower end of the strut extending and includes a generally curvilinear gull-wing shaped lower surface. For V-type hulls, a pair of elongated mechanical lifting structures, symmetrically positioned on either side of the keel substantially in the vicinity of the keel are attached to the hull so as to extend generally traversedly to the sloping side surfaces of the hull intersecting at the keel. These lifting structures have a length many times greater than their maximum transverse dimension and preferably extend from a position approximately a midship beneath the hull to the stern of the hull. Retractable hydrofoil assemblies are described for drawing a strut supporting a hydrofoil wing into a boat or rotating the strut upward into a tunnel beneath the boat in the case of a catamaran hull.
A FIFTH EXAMPLE, U.S. Pat. No. 4,915,048 to Stanford teaches planing vessels of improved performance capability and methods for improving such performance and foils which may be associated with planing vessels for providing improved performance capability. A dynamic downward force generated as the vessel moves through water, preferably by a foil, is imposed on the vessel, with the locus of the force positioned, in the traverse direction, at the longitudinal vertical centerline plane of the vessel. In the longitudinal direction the locus of the dynamic force is positioned, relative to the other forces acting fore-to-aft on the vessel, to decrease the trim angle of the vessel, desirably to less than two degrees. Vessel wetted surface configurations are provided for stable and efficient operation at low trim angles, including the following. A deep draft, fine entrance which minimizes rise at the bow experienced with conventional planing vessels and assists in maintaining laminarity of flow at the planing surfaces. A foil extending along the bowpeak below the waterline and spaced forwardly thereof to streamline the flow passing the bow to thereby decrease spray and turbulence. A skeg extending downward at the bottom of the hull at the entrance along the longitudinal centerline plane which improves directional stability and also assists in maintaining flow laminarity. A swept back wing located at the entrance, preferably mounted at the lower margin of the skeg positioned with an angle of attack which generates an upward force to improve the vessel stability against pitch and yaw in disturbed water. An aftmidships planing floor having a rise from midships to the stern trailing edge desirably from 50% to 100% of the midships draft improves the stability of the vessel when operated at trim. A release floor extending aftward 5 to 25% of the waterline length of the vessel, preferably from a transverse step and rising over this length 10 to 50% of the midships draft to a transverse trailing edge. The trailing edge and the release floor, in the transverse direction, are parallel with base plane of the vessel. The pressure release floor reduces the pressure on the aftward flow to separation at the trailing edge in a gradual and uniform manner which reduces drag. The foil to generate a downward force in the flow desirably is positioned below the stern trailing edge and contoured to produce minimum induced drag and to divert the flow at its trailing edge downwardly so as to reduce turbulence and drag at the stern.
A SIXTH EXAMPLE, U.S. Pat. No. 5,404,830 to Ligozio teaches a displacement boat hull having the outboard surfaces of its wetted portion designed with a deep-V shape, and having at least one pair of retractable hydrofoil fins positioned in respective pockets along those outboard surfaces at a predetermined distance above the keel. When extended, the fins are positioned at fixed angles relative to the hull, and at least one pair of fins is positioned in proximity to the stern. In a preferred embodiment, a conventional deep-V semi-displacement hull is modified to increase the conventional maximum draft with an unusually steep angle (at least 30 degrees to 40 degrees) for the initial deadrise from the keel upward toward the chine; and at least two pairs of fins are disposed on opposite sides of the hull, with an aft pair being positioned in proximity to the stern and another pair being positioned forward of the stern pair, preferably just forward of the boat""s center of balance. The fins are continuously adjustable from (a) a fully-retracted in-pocket position to a fully-extended position laterally outboard of the hull. The invention can be used to modify catamaran and tri-hulls as well as mono-hulls, and it is compatible with all types of propulsion systems. Such modifications provide a remarkably low center of gravity that assures excellent balance and stability at all times, particularly when operating with the fins, while achieving higher speeds and requiring less power.
A SEVENTH EXAMPLE, U.S. Pat. No. 6,164,235 to Hoppe teaches a hydrofoil equipment water craft comprising at least one hull member, terminating at a bow and a stern, a front hydrofoil member arranged in the zone of the bow of the hull, at least partially below the hull; and a rear hydrofoil member positioned to the rear of the longitudinal center of gravity (LCG) of the hull, the front hydrofoil member being at least partially offset transversely relative to the rear hydrofoil member so that the front hydrofoil or rear hydrofoil are at least partially disposed in separate longitudinal flow streams.
AN EIGHTH EXAMPLE, U.S. Pat. No. 6,354,237 B1 to Gaynor et al. teaches a trim tab control system in which four buttons or switches are provided for the marine operator in which the operator can select to raise the bow, raise the stern, raise the port side of the boat, or raise the stern side of the boat in relative terms, and the system will automatically position the trim tabs to most efficiently achieve the operator""s demanded change in position of the marine vessel.
It is apparent that numerous innovations for hydrofoils have been provided in the prior art that are adapted to be used. Furthermore, even though these innovations may be suitable for the specific individual purposes to which they address, however, they would not be suitable for the purposes of the present invention as heretofore described.
ACCORDINGLY, AN OBJECT of the present invention is to provide a hydrofoil system for lifting a boat out of water an amount sufficient to reduce drag while still allowing the boat to be powered by a conventional inboard-outboard drive that avoids the disadvantages of the prior art.
ANOTHER OBJECT of the present invention is to provide a hydrofoil system for lifting a boat out of water an amount sufficient to reduce drag while still allowing the boat to be powered by a conventional inboard-outboard drive that is simple and inexpensive to manufacture.
STILL ANOTHER OBJECT of the present invention is to provide a hydrofoil system for lifting a boat out of water an amount sufficient to reduce drag while still allowing the boat to be powered by a conventional inboard-outboard drive that is simple to use.
BRIEFLY STATED, STILL YET ANOTHER OBJECT of the present invention is to provide a hydrofoil system for lifting a boat out of water an amount sufficient to reduce drag while still allowing the boat to be powered by a conventional inboard-outboard drive. The hydrofoil system includes a front hydrofoil unit, a center hydrofoil unit, and a pair of rear hydrofoil units. The front hydrofoil unit includes a hydrofoil portion that dependingly mounts to a mounting portion thereof that depends from the bottom of the hull at the bow thereof. The center hydrofoil unit includes a hydrofoil that dependingly extends equidistantly outwardly from a pair of stanchions thereof that depend from the bottom of the hull at the substantial center thereof. Each rear hydrofoil unit includes a hydrofoil that dependingly extends equidistantly outwardly from a pair of stanchions thereof that depend from port and starboard trim tab units of the hull, respectively.
The novel features which are considered characteristic of the present invention are set forth in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of the specific embodiments when read and understood in connection with the accompanying drawing.